Synchronizing for digital content access control

ABSTRACT

A method and apparatus for digital content access control comprises determining the occurrence of a synchronization event that triggers synchronization of information used by one or more content provisioners to create an authenticated digital content request that is based at least in part on a digital content request comprising a request for digital content with information used by one or more content repositories to validate the authenticated digital content request and to return the digital content based at least in part on the validation. The method also comprises determining the information in response to the sychronization event and sending the information to at least one of the group comprising the one or more content provisioners and the one or more content repositories.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to the following:

U.S. patent application Ser. No. 10/014,893, filed Oct. 29, 2001 in thename of inventors Eduard de Jong, Moshe Levy and Albert Leung, entitled“User Access Control to Distributed Resources on a Data CommunicationsNetwork”, commonly assigned herewith, and now abandoned;

U.S. patent application Ser. No. 10/243,858, filed Sep. 13, 2002 in thename of inventors Eduard de Jong, Aaron Cooley and Jon Bostrom, entitled“System for Digital Content Access Control”, commonly assigned herewith,and issued as U.S. Pat. No. 7,363,651 on Apr. 22, 2008;

U.S. patent application Ser. No. 10/243,355, filed Sep. 13, 2002 in thename of inventors Eduard de Jong, Aaron Cooley and Jon Bostrom, entitled“Accessing for Digital Content Access Control”, commonly assignedherewith, and now abandoned;

U.S. patent application Ser. No. 10/243,474, filed Sept. 13, 2002 in thename of inventors Eduard de Jong, Aaron Cooley and Jon Bostrom, entitled“Repositing for Digital Content Access Control”, commonly assignedherewith, now U.S. Pat. No. 7,240,365 issued on Jul. 3, 2007;

U.S. patent application Ser. No. 11/717,740 filed on Mar. 12, 2007 inthe name of inventors Eduard de Jong, Aaron Cooley and Jon Bostrom,entitled “Repositing for Digital Content Access Control”, commonlyassigned herewith and which is a continuation of U.S. patent applicationSer. No. 10/243,474;

U.S. patent application Ser. No. 10/243,287, filed Sep. 13, 2002 in thename of inventors Eduard de Jong, Aaron Cooley and Jon Bostrom, entitled“Provisioning for Digital Content Access Control”, commonly assignedherewith, now abandoned;

U.S. patent application Ser. No. 10/040,270, filed Oct. 29, 2001 in thename of inventor Eduard de Jong et al., entitled “Enhanced PrivacyProtection in Identification in a Data Communications Network”, commonlyassigned herewith, now U.S. Pat. No. 7,275,260 issued on Sep. 25, 2007;

U.S. patent application Ser. No. 10/014,823, filed Oct. 29, 2001 in thename of inventors Eduard de Jong, Albert Y. Leung, and Moshe Levy,entitled “Enhanced Quality of Identification in a Data CommunicationsNetwork”, commonly assigned herewith, now U.S. Pat. No. 7,085,840 issuedon Aug. 1, 2006;

U.S. patent application Ser. No. 10/014,934, filed Oct. 29, 2001 in thename of inventors Eduard de Jong, Albert Y. Leung, and Moshe Levy,entitled “Portability and Privacy with Data Communications NetworkBrowsing”, commonly assigned herewith, and now abandoned;

U.S. patent application Ser. No. 10/033,373, filed Oct. 29, 2001 in thename of inventors Eduard de Jong, Albert Y. Leung, and Moshe Levy,entitled “Managing Identification in a Data Communications Network”,commonly assigned herewith, and now abandoned;

U.S. patent application Ser. No. 10/040,293, filed Oct. 29, 2001 in thename of inventors Eduard de Jong, Albert Y. Leung, and Moshe Levy,entitled “Privacy and Identification in a Data Communications Network”,commonly assigned herewith.

FIELD OF THE INVENTION

The present invention relates to the field of computer science. Moreparticularly, the present invention relates to a synchronizing fordigital content access control.

BACKGROUND OF THE INVENTION

FIG. 1 is a block diagram that illustrates a typical mechanism fordigital content access control. A mobile phone operator 100 includes aportal 150 by which one or more mobile phones 125-140 communicate withone or more content producers 105-120 via a network 175 such as theInternet. Mobile phone operator 100 also includes a product catalog 145that includes a description of digital content 155-170 stored by digitalcontent producers 105-170. A particular digital content producercontrols access to digital content stored by the digital contentproducer. Thus, authenticators 180-195 control access to digital content155-170, respectively.

A user desiring access to digital content 155-170 stored by a digitalcontent producer 105-120 uses a mobile phone 125-140 to issue an accessrequest to a particular digital content producer 105-120. The digitalcontent producer 105-195 authenticates the user making the request. Theauthentication typically includes prompting the user for a username anda password if the username and password is not included with the initialaccess request. Upon successful user authentication, the digital contentproducer 105-120 may grant access to the digital content 155-170.Alternatively, the digital content producer 105-120 may issue a tokenthat may be presented at a later time and redeemed in exchange foraccess to the digital content.

Unfortunately, the bandwidth available for communications with digitalcontent producers 105-120 is relatively limited. If the availablebandwidth is exceeded, a user may be denied service. This problem isexacerbated as the number of users increases.

Accordingly, a need exists in the prior art for a digital content accesscontrol solution that requires relatively less communication withdigital content producers. A further need exists for such a solutionthat is relatively secure. Yet another need exists for such a solutionthat is relatively scaleable.

SUMMARY OF THE INVENTION

A method and apparatus for digital content access control comprisesdetermining the occurrence of a synchronization event that triggerssynchronization of information used by one or more content provisionersto create an authenticated digital content request that is based atleast in part on a digital content request comprising a request fordigital content with information used by one or more contentrepositories to validate the authenticated digital content request andto return the digital content based at least in part on the validation.The method also comprises determining the information in response to thesychronization event and sending the information to at least one of thegroup comprising the one or more content provisioners and the one ormore content repositories.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and constitute apart of this specification, illustrate one or more embodiments of thepresent invention and, together with the detailed description, serve toexplain the principles and implementations of the invention.

In the drawings:

FIG. 1 is a block diagram that illustrates a typical mechanism fordigital content access control.

FIG. 2 is a block diagram of a computer system suitable for implementingaspects of the present invention.

FIG. 3 is a block diagram that illustrates a system for digital contentaccess control in accordance with one embodiment of the presentinvention.

FIG. 4 is a block diagram that illustrates a system for digital contentaccess control with a requesting user device and a receiving user devicein accordance with one embodiment of the present invention.

FIG. 5 is a block diagram that illustrates a system for digital contentaccess control using a portal in accordance with one embodiment of thepresent invention.

FIG. 6A is a diagram that illustrates a universal resource locator(URL).

FIG. 6B is a diagram that illustrates a tokenized URL having an appendedtoken in accordance with one embodiment of the present invention.

FIG. 6C is a diagram that illustrates a tokenized URL having an appendedparameterized token in accordance with one embodiment of the presentinvention.

FIG. 6D is a diagram that illustrates a tokenized URL for use inaccessing digital content at a content repository having an accessdomain dedicated to accepting tokenized URLs in accordance with oneembodiment of the present invention.

FIG. 6E is a diagram that illustrates a tokenized URL for use inaccessing digital content at a content repository having an accessdomain dedicated to accepting tokenized URLs in accordance with oneembodiment of the present invention.

FIG. 6F is a diagram that illustrates a tokenized URL for use inaccessing digital content at a particular content locker of a contentrepository having an access domain dedicated to accepting tokenized URLsin accordance with one embodiment of the present invention.

FIG. 7A is a diagram that illustrates a tokenized URL for use inaccessing a content repository having an access domain capable ofperforming functions in addition to accepting tokenized URLs inaccordance with one embodiment of the present invention.

FIG. 7B is a diagram that illustrates a tokenized URL for use inaccessing digital content at a content repository having an accessdomain capable of performing functions in addition to acceptingtokenized URLs in accordance with one embodiment of the presentinvention.

FIG. 7C is a diagram that illustrates a tokenized URL for use inaccessing digital content at a particular content locker of a contentrepository having an access domain capable of performing functions inaddition to accepting tokenized URLs in accordance with one embodimentof the present invention.

FIG. 8 is a block diagram that illustrates a system for program codemodule access control in accordance with one embodiment of the presentinvention.

FIG. 9 is a block diagram that illustrates a system for audio fileaccess control in accordance with one embodiment of the presentinvention.

FIG. 10 is a block diagram that illustrates a system for XML (ExtensibleMarkup Language) document access control in accordance with oneembodiment of the present invention.

FIG. 11 is a block diagram that illustrates a system for Web page accesscontrol in accordance with one embodiment of the present invention.

FIG. 12 is a block diagram that illustrates a system for digital contentaccess control having one or more content repositories associated with acontent provisioner in accordance with one embodiment of the presentinvention.

FIG. 13 is a block diagram that illustrates a system for digital contentaccess control having one or more content provisioners associated with acontent repository in accordance with one embodiment of the presentinvention.

FIG. 14 is a block diagram that illustrates a system for digital contentaccess control having one or more content provisioners and contentrepositories associated with a synchronizer in accordance with oneembodiment of the present invention.

FIG. 15 is a block diagram that illustrates a system for digital contentaccess control where a secure user device activates deactivated tokensissued by a content provisioner and uses the activated tokens to accessdigital content stored by a content repository in accordance with oneembodiment of the present invention.

FIG. 16 is a block diagram that illustrates a system for digital contentaccess control where a secure user device activates deactivated tokensissued by a content provisioner and uses the activated tokens to accessdigital content stored by a content repository in accordance with oneembodiment of the present invention.

FIG. 17 is a block diagram that illustrates token pool allocation andsynchronization in a system for digital content access control inaccordance with one embodiment of the present invention.

FIG. 18A is a diagram that illustrates a token in accordance with oneembodiment of the present invention.

FIG. 18B is a diagram that illustrates a token that comprises a chain IDin accordance with one embodiment of the present invention.

FIG. 18C is a diagram that illustrates a token that comprises a chain IDand a maximum length in accordance with one embodiment of the presentinvention.

FIG. 18D is a diagram that illustrates a token that comprises a chain IDand an identifier in a series in accordance with one embodiment of thepresent invention.

FIG. 18E is a diagram that illustrates a token that comprises a chain IDand an offset representing an identifier in a series in accordance withone embodiment of the present invention.

FIG. 18F is a diagram that illustrates a token that comprises a tokentype in accordance with one embodiment of the present invention.

FIG. 19 is a block diagram that illustrates creating a token chain byapplying a cryptographic process to one or more identifiers in a seriestogether with a token chain key in accordance with one embodiment of thepresent invention.

FIG. 20 is a block diagram that illustrates creating a token chain byapplying a cryptographic process to a filler and one or more identifiersin a series together with a token chain key in accordance with oneembodiment of the present invention.

FIG. 21 is a block diagram that illustrates creating a token chain usingcryptographic one-way functions in accordance with one embodiment of thepresent invention.

FIG. 22 is a flow diagram that illustrates a method for creating andusing a token pool formed by applying a cryptographic process to anidentifier in a series together with a token chain key in accordancewith one embodiment of the present invention.

FIG. 23 is a flow diagram that illustrates a method for creating andusing a token pool formed by successive applications of a cryptographicone-way function in accordance with one embodiment of the presentinvention.

FIG. 24 is a data flow diagram that illustrates communicating token poolinformation from a synchronizer in accordance with one embodiment of thepresent invention.

FIG. 25 is a block diagram that illustrates allocating tokens from atoken pool comprising one or more token chains created using acryptographic one-way function in accordance with one embodiment of thepresent invention.

FIG. 26 is a block diagram that illustrates a token pool having acurrent token pool for current token redemptions, a retired token poolfor tokens that have been available for redemption for a predeterminedtime and a buffered token pool for future token redemptions inaccordance with one embodiment of the present invention.

FIG. 27 is a detailed block diagram that illustrates initialization of asystem for digital content access control in accordance with oneembodiment of the present invention.

FIG. 28 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a user device in accordance withone embodiment of the present invention.

FIG. 29 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a secure user device inaccordance with one embodiment of the present invention.

FIG. 30 is a flow diagram that illustrates a method for initializing adigital content producer in accordance with one embodiment of thepresent invention.

FIG. 31 is a flow diagram that illustrates a method for initializing adigital content provisioner in accordance with one embodiment of thepresent invention.

FIG. 32 is a flow diagram that illustrates a method for contentrepository initialization in accordance with one embodiment of thepresent invention.

FIG. 33 is a flow diagram that illustrates a method for synchronizerinitialization in accordance with one embodiment of the presentinvention.

FIG. 34 is a detailed block diagram that illustrates a system fordigital content access control in accordance with one embodiment of thepresent invention.

FIG. 35 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a user device in accordance withone embodiment of the present invention.

FIG. 36 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a user device in accordance withone embodiment of the present invention.

FIG. 37 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a secure user device inaccordance with one embodiment of the present invention.

FIG. 38 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a digital content provisioner inaccordance with one embodiment of the present invention.

FIG. 39 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a digital content provisioner inaccordance with one embodiment of the present invention.

FIG. 40 is a flow diagram that illustrates a method for creating anauthenticated digital content request in accordance with one embodimentof the present invention.

FIG. 41 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a digital content repository inaccordance with one embodiment of the present invention.

FIG. 42 is a flow diagram that illustrates a method for validating anauthenticated digital content request using a pre-computed token poolcomprising multi-use tokens in accordance with one embodiment of thepresent invention.

FIG. 43 is a block diagram that illustrates a sliding token offsetwindow for use in dynamic token computation in accordance with oneembodiment of the present invention.

FIG. 44 is a flow diagram that illustrates a method for validating anauthenticated digital content request by dynamically computing tokensusing a sliding token offset window in accordance with one embodiment ofthe present invention.

FIG. 45 is a flow diagram that illustrates a method for validating anauthenticated digital content request by dynamically computing tokensusing a sliding token offset window having a dynamic size in accordancewith one embodiment of the present invention.

FIG. 46 is a flow diagram that illustrates a method for validating anauthenticated digital content request by dynamically computing tokensusing a sliding token offset window having a static size in accordancewith one embodiment of the present invention.

FIG. 47 is a flow diagram that illustrates a method for updating anoffset in accordance with one embodiment of the present invention.

FIG. 48 is a flow diagram that illustrates a method for validating anauthenticated digital content request using a pre-computed token poolcomprising single-use tokens computed using a cryptographic one-wayfunction in accordance with one embodiment of the present invention.

FIG. 49 is a flow diagram that illustrates a method for validating anauthenticated digital content request using a pre-computed token poolcomprising single-use tokens computed using a cryptographic one-wayfunction and ordered according to token redemption status in accordancewith one embodiment of the present invention.

FIG. 50 is a flow diagram that illustrates a method for validating anauthenticated digital content request by dynamically computingsingle-use tokens using a cryptographic one-way function in accordancewith one embodiment of the present invention.

FIG. 51 is a flow diagram that illustrates a method for digital contentaccess control from the perspective of a synchronizer in accordance withone embodiment of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention are described herein in the contextof synchronizing for digital content access control. Those of ordinaryskill in the art will realize that the following detailed description ofthe present invention is illustrative only and is not intended to be inany way limiting. Other embodiments of the present invention willreadily suggest themselves to such skilled persons having the benefit ofthis disclosure. Reference will now be made in detail to implementationsof the present invention as illustrated in the accompanying drawings.The same reference indicators will be used throughout the drawings andthe following detailed description to refer to the same or like parts.

In the interest of clarity, not all of the routine features of theimplementations described herein are shown and described. It will, ofcourse, be appreciated that in the development of any such actualimplementation, numerous implementation-specific decisions must be madein order to achieve the developer's specific goals, such as compliancewith application- and business-related constraints, and that thesespecific goals will vary from one implementation to another and from onedeveloper to another. Moreover, it will be appreciated that such adevelopment effort might be complex and time-consuming, but wouldnevertheless be a routine undertaking of engineering for those ofordinary skill in the art having the benefit of this disclosure.

In accordance with one embodiment of the present invention, thecomponents, process steps, and/or data structures may be implementedusing various types of operating systems (OS), computing platforms,firmware, computer programs, computer languages, and/or general-purposemachines. The method can be run as a programmed process running onprocessing circuitry. The processing circuitry can take the form ofnumerous combinations of processors and operating systems, or astand-alone device. The process can be implemented as instructionsexecuted by such hardware, hardware alone, or any combination thereof.The software may be stored on a program storage device readable by amachine.

In addition, those of ordinary skill in the art will recognize thatdevices of a less general purpose nature, such as hardwired devices,field programmable logic devices (FPLDs), including field programmablegate arrays (FPGAs) and complex programmable logic devices (CPLDs),application specific integrated circuits (ASICs), or the like, may alsobe used without departing from the scope and spirit of the inventiveconcepts disclosed herein.

In accordance with one embodiment of the present invention, the methodmay be implemented on a data processing computer such as a personalcomputer, workstation computer, mainframe computer, or high performanceserver running an OS such as Solaris® available from Sun Microsystems,Inc. of Santa Clara, Calif., Microsoft® Windows® XP and Windows® 2000,available form Microsoft Corporation of Redmond, Wash., or variousversions of the Unix operating system such as Linux available from anumber of vendors. The method may also be implemented on amultiple-processor system, or in a computing environment includingvarious peripherals such as input devices, output devices, displays,pointing devices, memories, storage devices, media interfaces fortransferring data to and from the processor(s), and the like. Inaddition, such a computer system or computing environment may benetworked locally, or over the Internet.

In the context of the present invention, the term “network” compriseslocal area networks, wide area networks, the Internet, cable televisionsystems, telephone systems, wireless telecommunications systems, fiberoptic networks, ATM networks, frame relay networks, satellitecommunications systems, and the like. Such networks are well known inthe art and consequently are not further described here.

In the context of the present invention, the term “randomized” describesthe result of a random or pseudo-random number generation process. A“randomized process” describes the application of such a result to aprocess. Methods of generating random and pseudo-random numbers areknown by those skilled in the relevant art.

In the context of the present invention, the term “identifier” describesone or more numbers, characters, symbols, or the like. More generally,an “identifier” describes any entity that can be represented by one ormore bits.

In the context of the present invention, the term “authenticator”describes an identifier for use in obtaining access to digital contentassociated with the authenticator.

In the context of the present invention, the term “token” describes anauthenticator comprising a cryptogram.

In the context of the present invention, the term “cryptographic one-wayfunction” describes any cryptographic process that produces an outputbased upon an input, such that it is computationally infeasible tocompute the input based upon the output. Exemplary cryptographic one-wayfunctions comprise the MD4 algorithm and the MD5 algorithm. The MD4algorithm is described in R. Rivest, The MD4 Message Digest Algorithm,Request for Comments (RFC) 1320, MIT Laboratory for Computer Science andRSA Data Security, Inc., April 1992. The MD5 algorithm is described inRivest. R. The MD5 Message-Digest Algorithm, Request for Comments (RFC)1321, MIT Laboratory for Computer Science and RSA Data Security, Inc.,April 1992.

FIG. 2 depicts a block diagram of a computer system 200 suitable forimplementing aspects of the present invention. As shown in FIG. 2,computer system 200 comprises a bus 202 which interconnects majorsubsystems such as a central processor 204, a system memory 206(typically RAM), an input/output (I/O) controller 208, an externaldevice such as a display screen 210 via display adapter 212, serialports 214 and 216, a keyboard 218, a fixed disk drive 220, a floppy diskdrive 222 operative to receive a floppy disk 224, and a CD-ROM player226 operative to receive a CD-ROM 228. Many other devices can beconnected, such as a pointing device 230 (e.g., a mouse) connected viaserial port 214 and a modem 232 connected via serial port 216. Modem 232may provide a direct connection to a server via a telephone link or tothe Internet via a POP (point of presence). Alternatively, a networkinterface adapter 234 may be used to interface to a local or wide areanetwork using any network interface system known to those skilled in theart (e.g., Ethernet, xDSL, AppleTalk™).

Many other devices or subsystems (not shown) may be connected in asimilar manner. Also, it is not necessary for all of the devices shownin FIG. 2 to be present to practice the present invention, as discussedbelow. Furthermore, the devices and subsystems may be interconnected indifferent ways from that shown in FIG. 2. The operation of a computersystem such as that shown in FIG. 2 is readily known in the art and isnot discussed in detail in this application, so as not to overcomplicatethe present discussion. Code to implement the present invention may beoperably disposed in system memory 206 or stored on storage media suchas fixed disk 220, floppy disk 224 or CD-ROM 228.

Turning now to FIG. 3, a block diagram that illustrates a system fordigital content access control in accordance with one embodiment of thepresent invention is presented. System 370 may comprise at least oneuser device 300, at least one content provisioner 315 and at least onecontent repository 320 that communicate via a network 310. System 370may also comprise a synchronizer 325 in communication with the contentprovisioner 315 and the content repository 320. User device 300 isconfigured to send a digital content request 350 and receive digitalcontent 365 in response to the digital content request 350.

User device 300 may be any device configured to render digital contentto a user 305. By way of example, user device 300 may comprise apersonal digital assistant (PDA), a personal computer (PC), a mobilephone, a server computer in communication with a user display, or thelike. According to another embodiment of the present invention, userdevice 300 comprises a secure portable device such as a Java Card™technology-enabled device, or the like. Java Card™ technology isdescribed in Chen, Z. Java Card™ Technology for Smart Cards—Architectureand Programmer's Guide, Boston, Addison-Wesley, 2000.

According to one embodiment of the present invention, user device 300comprises a CDMA technology-enabled smart card. CDMA technology-enabledsmart cards are described in Smart Card Stage I Description, Version1.1, CDMA Development Group—Smart Card Team Document (May 22, 1996).

According to another embodiment of the present invention, user device300 comprises a SIM (Subscriber Identity Module card) card. The term“SIM card” describes the smart card used in GSM (Global System forMobile Communications) mobile telephones. The SIM comprises thesubscriber's personal cryptographic identity key and other informationsuch as the current location of the phone and an address book offrequently called numbers. The SIM is described in Digital cellulartelecommunications system (phase 2+); Specification of the SubscriberIdentity Module—Mobile Equipment (SIM-ME) interface, ETSI, GSM 11.11version 7.4.0, Release 1998.

According to another embodiment of the present invention, user device300 comprises a WIM (Wireless Interface Module). A WIM is a smart cardin a WAP (Wireless Application Protocol) phone. It is described inWireless Identity Module Part: Security, WAP-260-WIM-20010712-a,Wireless Application Protocol Forum, Jul. 12, 2001.

According to another embodiment of the present invention, user device300 comprises a USIM (Universal Subscriber Identity Module). A USIM is asmart card for a 3GPP (3^(rd) Generation Partnership Project) mobilephone. It is described in 3rd Generation Partnership Project; TechnicalSpecification Terminals; USIM and IC card requirements, Release 4, 3GPPTS 21.111 V4.0.0 (2001-03).

According to another embodiment of the present invention, user device300 comprises a UIM (User Identity Module). A UIM is a smart card for a3GPP Project 2 (3GPP2) mobile phone. The term “R-UIM” is used when thesmart card is removable. A UIM is a super set of the SIM and allows CDMA(Code Division Multiple Access)-based cellular subscribers to roamacross geographic and device boundaries. The R-UIM is described in aspecification issued by the 3rd Generation Partnership Project 2 (3GPP2)and entitled 3rd Generation Partnership Project 2; Removable UserIdentity Module (R-UIM) for cdma2000 Spread Spectrum Systems, 3GPP2C.S0023-0, Jun. 9, 2000.

The above description regarding various mobile phone technologies is notintended to be limiting in any way. Those of ordinary skill in the artwill recognize that other user devices may be used.

Referring again to FIG. 3, content provisioner 315 is configured toreceive a digital content request 350 and return an authenticateddigital content request 355 in response to the received digital contentrequest 350. Content provisioner 315 may comprise a content rightsdatabase 330 to store an association between one or more users and adescription of the digital content that the one or more users areauthorized to access. Content provisioner 315 may also comprise aprovisioner manager 335 in communication with the content rightsdatabase 330. Provisioner manager 335 is configured to receive a digitalcontent request 350 and communicate with content rights database 330 todetermine whether the user 305 that made the request 350 is authorizedto access the digital content associated with the request 350.Provisioner manager 335 may comprise an issuer 375 to issue a token foruse in creating an authenticated digital content request 335.Alternatively, content provisioner 315 may comprise an issuer externalto and in communication with a provisioner manager. Provisioner manager335 is also configured to communicate with user device 300 to obtainuser authentication data such as a password, PIN, biometric data or thelike. If the user device 300 comprises a mobile phone, the userauthentication data may also comprise a mobile phone subscriber ID, orthe like. According to one embodiment of the present invention, theauthenticated digital content request 355 comprises a cryptogram basedat least in part on an identifier that describes the location of thedigital content for which access is authorized. According to anotherembodiment of the present invention, the cryptogram comprises at leastone token from a token pool associated with the location of the digitalcontent for which access is authorized.

Content repository 320 is configured to receive an authenticated digitalcontent request 360 and return digital content 365 corresponding to theauthenticated digital content request 360. Content repository 320 maycomprise a content database 340 to store digital content correspondingto at least one digital content description stored by at least onecontent provisioner 315. Content repository 320 also may comprise arepository manager 345 in communication with the content database 340.Repository manager 345 is configured to receive an authenticated digitalcontent request 360, communicate with the content database 340 todetermine whether the authenticated digital content request 360 is validand return the digital content associated with the authenticated digitalcontent request when the authenticated digital content request is valid.Repository manager 345 may also comprise an acceptor 380 to accept atoken and determine whether the access to the digital content associatedwith the authenticated digital content request is authorized based atleast in part on the token. Alternatively, content repository 320 maycomprise an acceptor external to and in communication with a repositorymanager 345.

Synchronizer 325 is configured to synchronize the information used bythe content provisioner 315 to create authenticated digital contentrequests with the information used by content repository 320 to validatedigital content requests. The authenticated digital content requestinformation may comprise, by way of example, a token pool, informationfor use in generating a token pool, and the number of tokens released bythe content provisioner 315. According to one embodiment of the presentinvention, the content provisioner 315 triggers the synchronization.According to another embodiment of the present invention, the contentrepository 320 triggers the synchronization. According to anotherembodiment of the present invention, the synchronization is triggered bythe synchronizer, based at least in part on a predetermined schedule.

According to one embodiment of the present invention, a contentprovisioner comprises a synchronizer (not shown in FIG. 3). According toanother embodiment of the present invention, a content repositorycomprises a synchronizer (not shown in FIG. 3).

In operation, user device 300 sends a digital content request 350 tocontent provisioner 315. According to one embodiment of the presentinvention, the digital content request 350 may be based at least in parton information received from content provisioner 315. This informationmay comprise, by way of example, an indication of one or more servicesavailable to user 305. Provisioner manager 335 in content provisioner315 receives the digital content request 350 and communicates withcontent rights database 330 to determine whether the user 305 that madethe request 350 is authorized to access the digital content associatedwith the request 350. Provisioner manager 335 may also communicate withuser device 300 to obtain user authentication data such as a password,PIN, biometric data or the like. If the user device 300 comprises amobile phone, the user authentication data may also comprise a mobilephone subscriber ID, or the like. If the user 305 that made the request350 is authorized to access the digital content 365 associated with thedigital content request 350, issuer 335 issues a token and provisionermanager 335 sends an authenticated digital content request 355 based atleast in part on the token to user device 300. User device 300 receivesthe authenticated digital content request 355 and then sends theauthenticated digital content request 360 to a content repository 320.Repository manager 345 in content repository 320 receives theauthenticated digital content request 320 and communicates with acceptor380 and content database 340 to determine whether the authenticateddigital content request 360 is valid. If the authenticated digitalcontent request 360 is valid, repository manager 345 returns the digitalcontent 365 associated with the authenticated digital content request360. User device 300 receives the digital content 365 for use by user305.

Turning now to FIG. 4, a block diagram that illustrates a system fordigital content access control with a requesting user device and areceiving user device in accordance with one embodiment of the presentinvention is presented. FIG. 4 is similar to FIG. 3, except that FIG. 4illustrates both a requesting user device 400 and a receiving userdevice 402.

Requesting user device 400 may be any device configured to accept userinput and communicate over a communications network 410. Receiving userdevice 402 may be any device configured to render digital content to auser 405. By way of example, user device 402 may comprise a PDA, a PC, amobile phone, a server computer in communication with a user display, orthe like.

In operation, requesting user device 400 communicates with contentprovisioner 415 to obtain an authenticated digital content request 455.The authenticated digital content request 455 may comprise one or moredelivery parameters that indicate a receiving user device to receivedigital content associated with the authenticated digital contentrequest 455. Alternatively, the authenticated digital content request455 may be used to obtain delivery information. Requesting user device400 sends the authenticated digital content request 460 to a contentrepository 420. Repository manager 445 in content repository 420receives the authenticated digital content request 420 and communicateswith acceptor 480 and content database 440 to determine whether theauthenticated digital content request 460 is valid. If the authenticateddigital content request 460 is valid, repository manager 445 sends thedigital content 465 associated with the authenticated digital contentrequest 460 to receiving device 402.

According to one embodiment of the present invention, requesting userdevice 400 comprises a user device having a relatively rich userinterface such as a mobile phone or the like and receiving user device402 comprises a user device having a relatively limited user interfacesuch as an MP3 (MPEG Audio Layer-3) player or the like.

Turning now to FIG. 5, a block diagram that illustrates a system fordigital content access control using a portal in accordance with oneembodiment of the present invention is presented. FIG. 5 is similar toFIG. 3, except that in FIG. 5, user device 500 communicates with contentrepository 520 via a portal operator 515 that comprises at least onecontent provisioner 535. Whereas in FIG. 3, user device 300 communicateswith content repository 320 directly via network 310.

In operation, user device 500 sends a digital content request 560 toportal 530 operated by portal operator 515. Portal 530 receives thedigital content request 560 and communicates with provisioner manager545 in content provisioner 535. Portal 530 may also communicate withuser device 500 to obtain user authentication data such as a password,PIN, biometric data or the like. If the user device 500 comprises amobile phone, the user authentication data may also comprise a mobilephone subscriber ID, or the like. Provisioner manager 545 receives thedigital content request 560 and communicates with content rightsdatabase 540 to determine whether the user 505 that made the request 560is authorized to access the digital content associated with the request560. If the user 505 that made the request 560 is authorized to accessthe digital content associated with the request 560, issuer 585 issuesan authenticator such as a token or the like and provisioner manager 545sends an authenticated digital content request 565 based at least inpart on the authenticator to content repository 520. Repository manager555 in content repository 520 receives the authenticated digital contentrequest 565 and communicates with acceptor 580 and content database 550to determine whether the authenticated digital content request 565 isvalid. The authenticated digital content request 565 is valid if thedigital content specified by the authenticated digital content requestis associated with the authenticator portion of the authenticateddigital content request. If the authenticated digital content request565 is valid, repository manager 555 returns the digital content 570associated with the authenticated digital content request 565. Portaloperator 515 receives the digital content 570 and sends the digitalcontent 575 to user device 500. User device 500 receives the digitalcontent 575 for use by user 505. Alternatively, repository manager 555may return the digital content 570 directly to user device 500 insteadof routing the digital content through the portal operator 515. Thedelivery method may be based at least in part on information from theauthenticated digital content request.

According to embodiments of the present invention, a token authenticatesa specification (such as a Universal Resource Locator (URL)) ofprotected digital content. Validation of a token comprises determiningwhether the token authenticates a specification of digital content forwhich access is requested. These concepts are described in more detailbelow with reference to FIGS. 6A-6F and FIGS. 7A-7C.

FIG. 6A is a diagram that illustrates a URL. Content domain indicator602 specifies the host name of a Web server. Content directory indicator604 specifies a directory at content domain 602 and accessed viadelivery scheme 600 where the digital content specified by content itemindicator 606 is stored. Exemplary delivery schemes comprise HTTP(Hypertext Transfer Protocol) and FTP (File Transfer Protocol).

FIGS. 6B-6F and 7A-7C are diagrams that illustrate tokenized URLs foruse in accessing digital content stored at a content repository inaccordance with embodiments of the present invention. FIG. 6Billustrates a tokenized URL having an appended token. FIG. 6Cillustrates a tokenized URL having an appended parameterized token. FIG.6D illustrates using a tokenized URL to provide relatively fine-grainedaccess control for digital content stored by a content repository havingan access domain dedicated to accepting tokenized URLs, while FIG. 6Fillustrates using a tokenized URL to provide relatively coarse-grainedaccess control for digital content stored by a content repository havingan access domain dedicated to accepting tokenized URLs. Similarly, FIG.7A illustrates using a tokenized URL to provide relatively fine-grainedaccess control for digital content stored by a content repository havingan access domain capable of performing functions in addition toaccepting tokenized URLs, while FIG. 7C illustrates using a tokenizedURL to provide relatively coarse-grained access control for digitalcontent stored by a content repository having an access domain capableof performing functions in addition to accepting tokenized URLs. FIGS.6B-6F and 7A-7C are discussed in more detail below.

FIG. 6B is a diagram that illustrates a tokenized URL having an appendedtoken in accordance with one embodiment of the present invention. Accessdomain indicator 612 in combination with delivery scheme indicator 610specifies the URL of a content repository. Content directory indicator614 specifies the pathname of a directory for at least one digitalcontent item. Content item indicator 616 specifies a pathname fordigital content located within content directory 614 at access domain612 for which access is requested and controlled by the token 618. Tokenindicator 618 specifies a token to use to access digital content withina context associated with the token. In this case, the contextassociated with the token comprises content item 616 within contentdirectory 614 located at access domain 612. The token specifies acollection of digital content items made accessible by the token.Presenting token 618 entitles the presenter access to digital content616 within content directory 614 at access domain 612.

FIG. 6C is a diagram that illustrates a tokenized URL having an appendedparameterized token in accordance with one embodiment of the presentinvention. FIG. 6C is similar to FIG. 6B except that a “Token=” namedparameter or keyword 638 is used to delimit a token 640 in FIG. 6C.

FIG. 6D is a diagram that illustrates a tokenized URL for use inaccessing digital content at a content repository having an accessdomain dedicated to accepting tokenized URLs in accordance with oneembodiment of the present invention. Access domain indicator 632 incombination with delivery scheme 650 specifies the URL of a contentrepository and token indicator 654 specifies a token to use to accessdigital content for a specific item located at access domain 632. Thetoken specifies a single digital content item made accessible by thetoken, thus providing relatively fine-grained access control. Presentingtoken 654 entitles the presenter access to digital content at accessdomain 632. According to one embodiment of the present invention,delivery parameter indicator 656 is derived from a rights database (suchas content rights database 540 of FIG. 5). Delivery parameter indicator656 may indicate, by way of example, a cryptographic protectionprotocol, a destination address, a process to perform on the digitalcontent before delivery, or any combination thereof. Delivery parameterindicator 656 may also comprise one or more content referenceparameters. According to another embodiment of the present invention,delivery scheme indicator 650 specifies a specialized protocol that isprivate to a user device and particular digital content. By way ofexample, delivery scheme indicator 650 may indicate a special protocolfor streaming media content.

FIG. 6E is a diagram that illustrates a tokenized URL for use inaccessing digital content at a content repository having an accessdomain dedicated to accepting tokenized URLs in accordance with oneembodiment of the present invention. Access domain indicator 662 incombination with delivery scheme indicator 660 specifies the URL of acontent repository. Content item indicator 666 specifies a pathname fordigital content located at access domain 662 and for which access isrequested and controlled by the token 664. Token indicator 664 specifiesa token to use to access digital content within a context associatedwith the token. In this case, the context associated with the tokencomprises content item 666 located at access domain 662. The token 664specifies a collection of digital content items made accessible by thetoken 664. Additional non-token information from content item 666 isrequired to completely specify the digital content accessed, thusproviding relatively coarse-grained access control with respect to theURL illustrated in FIG. 6D. Presenting token 664 entitles the presenteraccess to digital content 666 at access domain 662.

FIG. 6F is a diagram that illustrates a tokenized URL for use inaccessing digital content at a particular directory or content locker ofa content repository having an access domain dedicated to acceptingtokenized URLs in accordance with one embodiment of the presentinvention. Access domain indicator 672 in combination with deliveryscheme indicator 670 specifies the URL of a content repository. Contentlocker indicator 676 specifies the pathname of a container for at leastone digital content item. Content item indicator 678 specifies apathname for digital content located within content locker 676 at accessdomain 672 for which access is requested and controlled by the token674. Token indicator 674 specifies a token to use to access digitalcontent within a context associated with the token. In this case, thecontext associated with the token comprises content item 678 withincontent locker 676 located at access domain 672. The token specifies acollection of digital content items made accessible by the token.Additional non-token information from content locker indicator 676 andcontent item 678 are required to completely specify the digital contentaccessed, thus providing relatively coarse-grained access control withrespect to the URLs illustrated in FIGS. 6D and 6E. Presenting token 674entitles the presenter access to digital content 678 within contentlocker 676 at access domain 672.

In the context of the present invention, the term “servlet” comprises aprogram that resides and executes on a server to provide functionalityto the server or processing of data on the server. By way of example, aservlet may comprise a CGI (Common Gateway Interface) script or program,ASP (Active Server Pages), a Java™ Servlet, or the like. Java™ Servlettechnology is described in “Java™ Servlet Specification”, version 2.3,Sep. 17, 2001, available from Sun Microsystems, Santa Clara, Calif.According to embodiments of the present invention, a specialized servletis specified in an authenticated digital content request such as a URL.The specialized servlet handles the provisioning of digital contentprotected by authenticated digital content requests.

FIGS. 7A-7C are similar to FIGS. 6D-6F, respectively, except that theURLs in FIGS. 7A-7C additionally specify the pathname of a servlet (704,714, 734) to process an authenticated digital content request.

FIGS. 8-11 illustrate various apparatus for digital content accesscontrol in accordance with embodiments of the present invention. FIG. 8illustrates a system for controlling access to program code modules suchas MIDlets or the like. A MIDlet is an application that conforms to theMIDP (Mobile Information Device Profile) standard (Mobile InformationDevice Profile (JSR-37), JCP Specification, Java 2 Platform, MicroEdition, 1.0a, available from Sun Microsystems, Santa Clara Calif.).FIG. 9 illustrates a system for controlling access to audio files suchas MP3 files or the like. FIG. 10 illustrates a system for controllingaccess to XML (Extensible Markup Language) documents. FIG. 11illustrates a system for controlling access to Web pages.

According to embodiments of the present invention, user devicesillustrated in FIGS. 8-11 (reference numeral 800 of FIG. 8, referencenumeral 900 of FIG. 9, reference numeral 1000 of FIG. 10 and referencenumeral 1100 of FIG. 11) comprise a CDMA technology-enabled smart card,a SIM card, a WIM, a USIM, a UIM, a R-UIM or the like.

FIGS. 8-11 are intended for purposes of illustration and are notintended to be limiting in any way. Those of ordinary skill in the artwill recognize the invention may be applied to any digital contentregardless of digital content format or intended use.

FIGS. 12-14 illustrate systems for digital content access control havingalternative configurations. A user device is not shown in FIGS. 12-14and a content producer is not shown in FIGS. 12-15 to avoid obfuscationof the present invention.

Turning now to FIG. 12, a block diagram that illustrates a system fordigital content access control having one or more content repositoriesassociated with a content provisioner in accordance with one embodimentof the present invention is presented. System 1200 comprises a contentprovisioner 1205 in communication with one or more content repositories(1210, 1215) via network 1240. Content repositories 1210 and 1215comprise token acceptors 1225 and 1220, respectively. Contentprovisioner 1205 comprises a token issuer 1230 and a synchronizer 1235.Synchronizer 1235 maintains consistency in token pool information usedby token issuer 1235 and token acceptors 1225 and 1220.

Turning now to FIG. 13, a block diagram that illustrates a system fordigital content access control having one or more content provisionersassociated with a content repository in accordance with one embodimentof the present invention is presented. System 1300 comprises a contentrepository 1315 in communication with one or more content provisioners(1305, 1310) via network 1340. Content provisioners 1305 and 1310comprise token issuers 1320 and 1325, respectively. Content repository1315 comprises a token acceptor 1330 and a synchronizer 1335.Synchronizer 1335 maintains consistency in token pool information usedby token acceptor 1330 and token issuers 1305 and 1310.

Turning now to FIG. 14, a block diagram that illustrates a system fordigital content access control having one or more content provisionersand content repositories associated with a synchronizer in accordancewith one embodiment of the present invention is presented. System 1400comprises one or more content provisioners (1405, 1410), one or morecontent repositories (1420, 1425) and a synchronizer 1415 incommunication via network 1450. Content provisioners 1405 and 1410comprise token issuers 1430 and 1435, respectively. Content repositories1420 and 1425 comprise token acceptors 1440 and 1445, respectively.Synchronizer 1415 maintains consistency in token pool information usedby token issuers 1430 and 1435, token acceptors 1440 and 1445 andsynchronizer 1415. Synchronizer 1415 may be operated by a trusted thirdparty such as a financial services provider or bank.

Turning now to FIG. 15, a block diagram that illustrates a system fordigital content access control where a secure user device activatesdeactivated tokens issued by a content provisioner and uses theactivated tokens to access digital content stored by a contentrepository in accordance with one embodiment of the present invention ispresented. System 1500 comprises a content provisioner 1505, a contentrepository 1515, a user device 1565 and a synchronizer 1520 incommunication via network 1560. Content provisioner 1505 comprises atoken issuer 1535 and content repository 1515 comprises a token acceptor1540. User device 1565 comprises storage for deactivated tokens (1570).User device 1565 also comprises a secure user device 1510 that comprisesa co-issuer 1525. The co-issuer 1525 comprises a secret 1530 foractivating deactivated tokens.

In operation, user device 1565 communicates with content provisioner1505 to obtain one or more deactivated tokens and stores them indeactivated token storage 1570. The one or more deactivated tokens 1545are tied to particular digital content. Co-issuer 1525 activates the oneor more deactivated tokens 1545 based at least in part on secret 1530.Secure user device 1505 presents one or more activated tokens 1550 tocontent repository 1515 to receive access to the digital contentassociated with the one or more activated tokens 1550. Contentrepository 1515 presents synchronizer 1555 with accepted tokens 1555.The synchronizer 1520 may recycle the previously accepted tokens 1555 tomake them available for future token allocations. Synchronizer 1520 mayalso facilitate payment for delivery of digital content and receivepayment in return for the accepted tokens. Synchronizer 1520 presentstokens to be recycled 1575 to content provisioner 1505 for subsequentreuse.

According to one embodiment of the present invention, user device 1565comprises a mobile phone and secure user device 1505 comprises a SIMcard or the like.

According to one embodiment of the present invention, co-issuer 1525activates one or more deactivated tokens 1545 upon receipt by secureuser device 1505 and stores the activated tokens in secure user device1505 until the activated tokens are redeemed for access to digitalcontent associated with the tokens. According to another embodiment ofthe present invention, secure user device 1505 stores one or moredeactivated tokens until access to digital content associated with thedeactivated tokens is desired. At that point, co-issuer 1525 activatesthe deactivated tokens and presents the activated tokens 1550 to contentrepository 1515 for access to digital content associated with theactivated tokens.

Turning now to FIG. 16, a block diagram that illustrates a system fordigital content access control where a secure user device activatesdeactivated tokens issued by a content provisioner and uses theactivated tokens to access digital content stored by a contentrepository in accordance with one embodiment of the present invention ispresented. FIG. 16 is similar to FIG. 15 except that secure user device1610 in FIG. 16 comprises deactivated token storage 1670. In operation,user device 1665 communicates with content provisioner 1605 to obtainone or more deactivated tokens and stores them in deactivated tokenstorage 1670. The one or more deactivated tokens 1645 are tied toparticular digital content. Co-issuer 1625 activates the one or moredeactivated tokens 1645 based at least in part on secret 1630. Secureuser device 1610 presents one or more activated tokens 1650 to contentrepository 1615 to receive access to the digital content associated withthe one or more activated tokens 1650. Content repository 1615 presentssynchronizer 1620 with accepted tokens 1655. The synchronizer 1620 mayrecycle the previously accepted tokens 1655 to make them available forfuture token allocations. Synchronizer 1620 may also facilitate paymentfor delivery of digital content and receive payment in return for theaccepted tokens. Synchronizer 1620 presents tokens to be recycled 1675to content provisioner 1605 for subsequent reuse.

Turning now to FIG. 17, a block diagram that illustrates token poolallocation and synchronization in a system for digital content accesscontrol in accordance with one embodiment of the present invention ispresented. According to embodiments of the present invention, acollection of one or more tokens tied to or associated with particulardigital content is referred to as a token pool. A token issuer 1705 isassociated with one or more issuer token pools 1720. The token issuer1705 accounts for issued and available tokens. A token acceptor 1710 isassociated with one or more acceptor token pools 1725. The tokenacceptor 1710 accounts for unredeemed tokens and tokens that have beenpartially and fully redeemed for access to digital content associatedwith the token pool 1725. A token is fully redeemed if it has beenredeemed a predetermined number of times. A token is not fully redeemedif it has been redeemed less than the predetermined number of times. Atoken is partially redeemed if it has been redeemed a number of timesthat is greater than zero but less than the predetermined number oftimes. Issuer token pool 1720 and acceptor token pool 1725 areassociated with the same digital content. Synchronizer 1715 synchronizesthe token pool information for issuer token pool 1720 and acceptor tokenpool 1725. When issuer 1705 needs to provision tokens for digitalcontent that the issuer 1705 does not currently manage, issuer 1705issues a new pool request 1740. Synchronizer receives the request 1740and provides the issuer 1710 and the acceptor 1710 with at least one newtoken pool 1745 associated with the new digital content.

Still referring to FIG. 17, issuer 1705 or acceptor 1710 may requestadditional tokens when a requirement for more is determined. The issuermay make this determination based at least in part on factors such asthe number of unissued tokens remaining in a particular issuer tokenpool or the amount of time since new tokens were received, by way ofexample. The acceptor may determine that more tokens are required basedat least in part on factors such the number of unredeemed and partiallyredeemed tokens remaining in a particular acceptor token pool or theamount of time since new tokens were received, by way of example. Thesynchronizer 1715 may also determine that more tokens are required basedat least in part on factors such as the amount of time since a tokenpool was replenished. When a requirement for more tokens is determined,synchronizer 1715 provides issuer 1705 and acceptor 1710 with one ormore additional tokens.

Still referring to FIG. 17, various transport mechanisms may be used tocommunicate information such as token pool information between thesynchronizer 1715, issuer 1705 and acceptor 1710 entities. The transportmechanism may be based at least in part on the level of trust betweenthe entities. If there is a relatively high level of trust between theentities, synchronizer 1715 may provide issuer 1705 and acceptor 1710with the tokens for a token pool. If there is a relatively low level oftrust between the entities, synchronizer 1715 may provide issuer 1705and acceptor 1710 with a cryptogram or sealed message that comprisestokens or information for use in generating the tokens.

According to another embodiment of the present invention, token poolinformation is communicated from a content provisioner to a contentrepository using SSL (Secure Sockets Layer) or the like. Those ofordinary skill in the art will recognize that token pool information maybe communicated securely from a content provisioner to a contentrepository using other mechanisms.

FIGS. 18A-18F illustrate tokens in accordance with embodiments of thepresent invention. A token may comprise a cryptogram as illustrated inFIG. 18A. Cryptogram 1800 may be based at least in part on the digitalcontent associated with the token, or on a reference to the digitalcontent. In other words, cryptogram 1800 may authenticate the protecteddigital content or a reference to the protected digital content. In FIG.18B, the token comprises a cryptogram 1810 and a chain ID 1805. Chain ID1805 may be used to associate the token with a token pool or token chainwithin a token pool. According to one embodiment of the presentinvention, Chain ID 1805 is based at least in part on a token chain key.According to another embodiment of the present invention, chain ID 1805comprises a pool ID and chain ID corresponding to a token chain withinthe token pool associated with the pool ID. In FIG. 18C, the tokencomprises a cryptogram 1825, a chain ID 1815 and a maximum chain length1820. In FIG. 18D, the token comprises a cryptogram 1840, a chain ID1830 and an offset or identifier in a series 1835. Offset 1835 may beused to identify the position within a token pool or token chain wherethe cryptogram 1840 is located. In other words, offset 1835 may be usedto identify the location of a cryptogram 1840 in a token pool or tokenchain. In FIG. 18E, the token comprises a cryptogram 1855, a chain ID1845 and an offset representing an identifier in a series 1850. In FIG.18F, the token comprises a cryptogram 1870 and a token type indicator1860. Token type indicator 1860 specifies the format of the token (i.e.what to expect in token fields 1865 and 1870). Reference numeral 1865represents one or more token fields. By way of example, referencenumeral 1865 may comprise one or more of the fields illustrated in FIGS.18A-18E, and token type indicator 1860 may specify the format of tokenfields 1865 and 1870.

The token formats illustrated in FIGS. 18A-18F are for purposes ofillustration and are not intended to be limiting in any way. A token mayalso comprise an Extensible Markup Language (XML)-formatted HypertextMarkup Language (HTML)-encoded message with fields as illustrated inFIGS. 18A-18E. Additionally, a cryptogram may comprise other fields andother combinations of fields illustrated in FIGS. 18A-18F.

According to embodiments of the present invention, a token poolcomprises one or more token chains that comprise one or more tokens.FIGS. 19, 20 and 21 illustrate creating tokens for subsequent use increating a tokenized URL. FIG. 19 illustrates creating a token chain byapplying a cryptographic process to one or more identifiers in a seriestogether with a token chain key, FIG. 20 illustrates creating a tokenchain by applying a cryptographic process to a filler and one or moreidentifiers in a series together with a token chain key, and FIG. 21illustrates creating a token chain using cryptographic one-wayfunctions.

Turning now to FIG. 19, a block diagram that illustrates creating atoken chain by applying a cryptographic process to one or moreidentifiers in a series together with a token chain key with inaccordance with one embodiment of the present invention is presented.Token chain 1944 comprises a plurality of tokens 1930-1938. Seed 1904may be based at least in part on a portion of a URL, where the URLdefines digital content that may be accessed using a token from a tokenpool based at least in part on the seed 1904. According to oneembodiment of the present invention, a cryptographic process (1906) isapplied to seed 1904 to create a token chain key 1908. According to oneembodiment of the present invention, the cryptographic process (1906)comprises a hashing function. According to another embodiment of thepresent invention, the token chain key 1908 is created by applying acryptographic process (1906) to the seed 1904 together with a token poolkey 1900. According to another embodiment of the present invention, thetoken chain key 1908 is created by applying a cryptographic process(1906) to the seed 1904 and the maximum length of the token chain 1902.Tokens 1930-1938 are created by applying a cryptographic process to(1910-1918) identifiers 1920-1928, respectively, together with the tokenchain key 1908.

Turning now to FIG. 20, a block diagram that illustrates creating atoken chain by applying a cryptographic process to a filler and one ormore identifiers in a series together with a token chain key inaccordance with one embodiment of the present invention is presented.Tokens 2030-2038 are created by replacing a predefined set of bits of afiller 2046 with the one or more bits expressing an identifier in aseries (2020-2028) and applying a cryptographic process (2010-2018) tothe modified filler 2046 together with the token chain key 2008.According to one embodiment of the present invention, tokens areallocated in order of token creation. Tokens may be pre-generated.Alternatively, the last identifier used to generate a token is storedand this stored value is used to generate tokens one-at-a-time asneeded.

Turning now to FIG. 21, a block diagram that illustrates creating atoken chain using cryptographic one-way functions in accordance with oneembodiment of the present invention is presented. Token chain key 2100is used to create the first token 2140 and tokens 2145-2155 are based atleast in part on tokens 2140-2150, respectively. Token 2160 is based atleast in part on the token that precedes it (the token corresponding toposition M (2185) minus one). According to one embodiment of the presentinvention, the token allocation order is the reverse of the tokengeneration order. Using FIG. 21 as an example, the last-generated token2160 is also the first-allocated token. Similarly, the first-generatedtoken 2140 is also the last-allocated token.

According to one embodiment of the present invention, the first token2140 is created by applying a cryptographic process (2115) to a lengthvalue 2105 that indicates the number of tokens in the correspondingtoken chain 2102, together with a token chain key 2100. According to oneembodiment of the present invention, the cryptographic process (2115)comprises a hashing function. According to another embodiment of thepresent invention, the first token 2140 is created by applying acryptographic process (2115) to the token chain key 2100 together with atoken pool key 2110 that is shared by token chains within a token pool.According to another embodiment of the present invention, the firsttoken 2140 is created by applying a cryptographic process (2115) to alength value 2105 and the token chain key 2100 together with a tokenpool key 2110.

The data used to create the first token 2140 determines how tokenvalidation is performed. By way of example, length value 2105 may befixed for a particular token pool and known to both token issuer andtoken acceptor. In this case, both the issuer and the acceptor maygenerate tokens in a token chain associated with token chain key 2100independent of whether a synchronizer provides a length value with atoken chain key 2100. However, if the length field 2105 is not known toboth issuer and token acceptor and if the length value is used to createthe first token 2140, a synchronizer may provide the length value 2105with the associated token chain key 2100. Alternatively, a token maycomprise a length value as illustrated above with respect to referencenumeral 1820 of FIG. 18.

Turning now to FIG. 22, a flow diagram that illustrates a method forcreating and using a token pool formed by applying a cryptographicprocess to an identifier in a series together with a token chain key inaccordance with one embodiment of the present invention is presented.FIG. 22 corresponds to FIG. 19. At 2200, a token pool that comprises atoken chain where each token in a token chain is formed by applying acryptographic process to one or more bits expressing an identifier in aseries together with a token chain key is created. At 2205, the tokensin the token chain are allocated based on authenticated user requestsfor one or more resources associated with the token pool. According toone embodiment of the present invention, token allocation is orderedaccording to the token creation order such that the first-allocatedtoken comprises the first-created token and the last-allocated tokencomprises the last-created token. According to another embodiment of thepresent invention, a randomized process is used to select an unallocatedtoken within the token chain.

The process corresponding to FIG. 20 is similar to the flow diagramillustrated in FIG. 22, except that at reference numeral 2200, eachtoken in a token chain is formed by replacing a predefined set of bitsof a filler with the one or more bits expressing an identifier in aseries and applying a cryptographic process to the modified fillertogether with a token chain key.

Turning now to FIG. 23, a flow diagram that illustrates a method forcreating and using a token pool formed by successive applications of acryptographic one-way function in accordance with one embodiment of thepresent invention is presented. FIG. 23 corresponds to FIG. 21. At 2300,a token pool that comprises a token chain where each token in a tokenchain is formed by applying a cryptographic one-way function to thetoken immediately preceding the current token in the token chain iscreated. At 2305, the tokens in the token chain are allocated in reversesequential order based on authenticated user requests for one or moreresources associated with the token pool, beginning with thelast-created token in the token chain.

As mentioned with reference to FIG. 17, a synchronizer communicatestoken validation information to a content repository that allows thecontent repository to validate received tokens. The token validationinformation may comprise one or more token pools or information used togenerate the pools. The synchronizer may transfer the token validationinformation using a secure protocol such as SSL or the like.Alternatively, the synchronizer may transfer encrypted token validationinformation. This encrypted token validation information may also betransferred using a further secure protocol such as SSL or the like.

According to one embodiment of the present invention, the tokenvalidation information transferred by a synchronizer comprises a tokenpool. In response to a token synchronization event (such as when arequesting entity requests an additional token pool), a synchronizergenerates a token pool comprising tokens and sends the tokens to therequesting entity and optionally to one or more non-requesting entities.The requesting entity and the non-requesting entities may comprise acontent repository or a content provisioner. If the requesting entity isa content repository, content repository receives the token pool anduses it to validate authenticated digital content requests. If therequesting entity is a content provisioner, the content provisionerreceives the token pool and uses it to generate authenticated digitalcontent requests.

According to another embodiment of the present invention, a tokencomprises a chain ID as illustrated in FIGS. 18B-18E. In this case, thesynchronizer transfers token pool keys. Upon receiving an authenticateddigital content request, the content repository uses the chain ID of thereceived token to determine which token chain to check. If the contentrepository is configured to pre-compute token pools, the token chainassociated with the received chain ID is checked for the cryptogramassociated with the received token. If the content repository is notconfigured to pre-compute token pools, the chain ID is used in thecomputation to check the cryptogram associated with the received token,which comprises generating all or part of the token chain. Upon theoccurrence of a synchronization event, such as when the amount of tokensavailable for redemption falls below a predetermined threshold, thesynchronizer sends one or more token pool keys.

FIG. 24 illustrates transferring one or more token chain keys andpossibly additional information from a synchronizer. A cryptographicprocess 2426 is applied to a portion (2420, 2422, 2424) of a URL 2462,together with a key 2428. The URL 2462 identifies the protected digitalcontent. According to one embodiment of the present invention, the URLcomprises a content domain indicator (2420). According to anotherembodiment of the present invention, the URL comprises a content domainindicator and a content directory indicator (2422). According to anotherembodiment of the present invention, the URL comprises a content domainindicator, a content directory indicator and a content item indicator(2424). The cryptographic process may additionally be applied to arandomized number 2466 or a chain length 2435. According to oneembodiment of the present invention, the cryptographic process comprisesencryption. According to another embodiment of the present invention,the cryptographic process comprises a hashing function. The result ofthe cryptographic process is a token chain key 2430. The token chain key2430 is encrypted with a transport key 2436, creating sealed token poolinformation 2438. A chain length, a portion of a URL 2462, or both mayalso be encrypted at 2432.

Still referring to FIG. 24, the decision regarding whether to encryptthe chain length or the URL at 2432 may be based on factors such as alevel of trust with the receiving entity, and whether cryptographicprocess 2426 is reversible. If cryptographic process 2426 isirreversible and if the receiving entity requires additional informationsuch as the chain length and the URL, the additional information isincluded in the data encrypted at 2432. The sealed token poolinformation 2438 may be communicated to a content provisioner for use inissuing authenticated digital content requests. The sealed token poolinformation may also be communicated to a content repository for use invalidating authenticated digital content requests.

According to one embodiment of the present invention, cryptographicprocess 2426 corresponds to cryptographic process 1906 in FIG. 19.According to another embodiment of the present invention, cryptographicprocess 2426 corresponds to cryptographic process 2006 in FIG. 20.According to one embodiment of the present invention, cryptographicprocess 2426 corresponds to cryptographic process 2115 in FIG. 21. Thoseof ordinary skill in the art will recognize that other cryptographicprocesses may be used.

Still referring to FIG. 24, at 2440 a receiving entity such as a contentrepository or a content provisioner receives the sealed token poolinformation 2438 and decrypts it using a transport key 2442 agreed withthe synchronizer. The contents of the unsealed token pool informationdepend upon what was input to the encryption process at 2432. As shownin FIG. 24, the unsealed token pool information comprises a token chainkey 2446, a chain length 2444 and a portion of a URL 2448. A tokengeneration process 2454 uses the unsealed token pool information togenerate a token pool 2452. If the receiving entity is a contentprovisioner, the tokens in the token pool are used to createauthenticated digital content requests. If the receiving entity is acontent repository, the tokens in the token pool are used to validateauthenticated digital content requests.

The mechanisms used to communicate token pool information as shown anddescribed with respect to FIG. 24 are for illustrative purposes only andare not intended to be limiting in any way. Other cryptographic methodsand sealed data may be used.

FIGS. 25 and 26 illustrate token pools comprising one or more tokenchains that comprise one or more tokens in accordance with embodimentsof the present invention. FIG. 25 illustrates a single token pool thatcomprises one or more token chains created using cryptographic one-wayfunctions, and FIG. 26 illustrates a single token pool that comprisesone or more smaller token pools that may be organized as described withrespect to FIG. 25.

As mentioned above, the term “cryptographic one-way function” describesany cryptographic process that produces an output based upon an input,such that it is computationally infeasible to compute the input basedupon the output. However, it is less difficult to compute alater-generated token when an earlier-generated token is known.Therefore, it may be possible to receive an earlier-generated token andcompute a later-generated token that has been issued but has not beenredeemed. This computed token may then be used to obtain unauthorizedaccess to digital content and consequently prevent the authorizedrecipient of the token from using the token to obtain access to digitalcontent. According to one embodiment of the present invention, a tokenpool comprises one or more token chains created using cryptographicone-way functions. Tokens are issued from alternating chains, decreasingthe per-token-chain number of tokens that have been issued but have notbeen redeemed, and thus decreasing the likelihood that a valid butunauthorized token may be computed based upon a previously generatedtoken. This is explained in more detail below with reference to FIG. 25.

Turning now to FIG. 25, a block diagram that illustrates allocatingtokens from a token pool comprising one or more token chains createdusing a cryptographic one-way function in accordance with one embodimentof the present invention is presented. Token pool 2500 comprises tokenchains 2504-2528. Token chains 2504-2528 comprise a predetermined numberof tokens. According to one embodiment of the present invention, a tokenin a token chain is formed by applying a cryptographic one-way functionto the previous token as illustrated with respect to FIGS. 21 and 23.

According to one embodiment of the present invention, tokens in a tokenpool as illustrated in FIG. 25 are allocated with each successive tokenallocation originating from a token chain that is different than thelast. Where tokens in a token pool are based upon encrypting a number ina series as illustrated with respect to FIGS. 19, 20 and 22, arandomized selection process may be used to select an unallocated tokenfrom a particular token chain.

According to another embodiment of the present invention, tokens in atoken pool as illustrated in FIG. 25 are allocated beginning with thelast-generated token 2530 in the first token chain 2504 and continuingin a diagonal pattern. Cryptographic one-way functions are used tocreate the tokens in the token chains. Since the per-chain tokenallocation order is the reverse of the token generation order,allocation of the first-generated token indicates the token chain hasbeen fully allocated. Accordingly, one or more additional token chainsare requested upon allocating the first-generated token in what iscurrently the last token chain. This obviates the need for a morecomplex mechanism for determining whether another token chain should berequested, such as counting the number of tokens allocated andrequesting an additional chain at predetermined intervals.

FIG. 25 shows the state of token pool 2500 after several tokens havebeen allocated. As shown in FIG. 25, all tokens in token chain 2504 havebeen allocated, token chains 2506-2522 are partially allocated and tokenchains 2524-2528 are unallocated. Diagonal 2532 indicates thelast-allocated tokens and diagonal 2534 indicates the tokens to beallocated next, beginning with token 2536 and ending with token 2538.According to one embodiment of the present invention, a determinationregarding whether to request additional token chains is made uponallocating the last token in a token chain. Using FIG. 25 as an example,the previous determination regarding whether to request additional tokenchains was made upon allocating token 2538, the current determination ismade upon allocating token 2536 and the next determination will be madeupon allocating token 2538. The determination may be based at least inpart on one or more factors such as the number of tokens per chain andthe token allocation rate.

The number of token chains and the number of tokens in each token chainas shown in FIG. 25 are not intended to be limiting in any way. Those ofordinary skill in the art will recognize that the number of tokens ineach token chain and the number of token chains in a token pool mayvary. Additionally, the number of tokens in each token chain need not beuniform with respect to one or more token chains within a token pool.

According to embodiments of the present invention, a token poolcomprises a plurality of smaller token pools. This is described below indetail with reference to FIG. 26.

Turning now to FIG. 26, a block diagram that illustrates a token poolhaving a current token pool for current token redemptions, a retiredtoken pool for tokens that have been available for redemption for apredetermined time and a buffered token pool for future tokenredemptions in accordance with one embodiment of the present inventionis presented. In operation, a content repository satisfies tokenredemption requests from a current token pool 2615 and a retired tokenpool 2610. An indication is made when a token is redeemed so that atoken is redeemed a predetermined number of times. According to oneembodiment of the present invention, this predetermined number of timesis one. When the decision is made to start satisfying token redemptionrequests from a new token pool, the retired token pool 2610 isdiscarded, the current token pool 2615 becomes the retired token pool2610, the buffered token pool 2605 becomes the current token pool 2615and a new buffered token pool 2605 is received.

According to one embodiment of the present invention, the decision tostart satisfying token redemption requests from a new token pool isbased at least in part on the number of unredeemed tokens remaining inthe current token pool 2615. By way of example, a content repository maybe configured such that redemption requests begin to be satisfied from anew token pool when the number of tokens not fully redeemed remaining inthe current token pool falls below ten.

According to another embodiment of the present invention, the decisionto start satisfying token redemption requests from a new token pool isbased at least in part on the amount of time that the current token poolhas been available for satisfying token redemption requests. By way ofexample, a content repository may be configured such that redemptionrequests begin to be satisfied from a new token chain when a currenttoken chain has been available for satisfying token redemption requestsfor ten or more minutes.

According to another embodiment of the present invention, the decisionto start satisfying token redemption requests from a new token pool isbased at least in part on instructions provided by an external source,such as a content provisioner. By way of example, a content repositorymay be configured begin satisfying token redemption requests from a newtoken pool when instructed to do so by a digital content provisioner.

FIGS. 27-33 illustrate initialization of a system for digital contentaccess control in accordance with embodiments of the present invention.FIGS. 34-51 illustrate operation of a system for digital content accesscontrol in accordance with embodiments of the present invention.

Turning now to FIG. 27, a detailed block diagram that illustratesinitialization of a system for digital content access control inaccordance with one embodiment of the present invention is presented.System 2746 comprises at least one user device 2700, at least onecontent provisioner 2734, at least one content repository 2708 and atleast one content producer 2710 that communicate via network 2706. Userdevice 2700 is configured to send a digital content request and receivedigital content in response to the digital content request. User device2700 may be any device configured to render digital content to a user2702.

According to embodiments of the present invention, user device 2700comprises a CDMA technology-enabled smart card, a SIM card, a WIM, aUSIM, a UIM, a R-UIM or the like.

Content provisioner 2724 is configured to receive a digital contentrequest and return an authenticated digital content request in responseto the received digital content request. Content provisioner 2724comprises a provisioner manager 2704, a content rights database 2714 anda content catalog 2722. Content rights database 2714 is configured tostore an association between one or more users 2702 and a description ofthe digital content that the one or more users are authorized to access.Content catalog 2722 comprises a description of digital content storedby one or more digital content repositories 2708.

Still referring to FIG. 27, provisioner manager 2704 comprises a tokenissuer 2720, a download manager 2716, a content descriptor loader 2718and a synchronizer 2730. Content descriptor loader 2718 is configured toload one or more content, descriptors provided by one or more contentproducers 2710. Download manager 2716 is configured to receive a digitalcontent request such as a portion of a URL or the like and communicatewith content rights database 2722 to determine whether the user isauthorized to access the digital content. Download manager 2716 is alsoconfigured to send a token request if access is authorized, receive therequested token and create an authenticated digital content requestbased at least in part on the token and the digital content request.Synchronizer 2730 is configured to synchronize token information betweencontent provisioner 2724 and content repository 2708. According to oneembodiment of the present invention, an authenticated digital contentrequest comprises a tokenized URL.

Still referring to FIG. 27, download manager 2716 is also configured tosend the authenticated digital content request. Token issuer 2720 isconfigured to receive a token request, generate a token associated withthe digital content for which access is requested, and return the token.

Content repository 2708 is configured to receive an authenticateddigital content request and return digital content corresponding to theauthenticated digital content request. Content repository 2708 comprisesa repository manager 2744 and a database 2738. Database 2738 comprisesdigital content 2740 and a token pool 2742 associated with the digitalcontent 2740.

Still referring to FIG. 27, repository manager 2744 comprises a tokenacceptor 2734. Token acceptor 2734 is configured to accept digitalcontent request information. The authenticated digital content requestinformation may comprise, by way of example, a token pool, informationfor use in generating a token pool, and the number of tokens released bythe content provisioner. The information may also comprise one or moretoken chain keys and corresponding token chain lengths. Token acceptor2734 is also configured to accept a token and communicate with tokenpool 2742 to determine whether the token is valid for the digitalcontent requested.

Content producer 2710 is configured to provide digital content tocontent repository 2708. Content producer 2710 is also configured toprovide at least one digital current description corresponding to thedigital content stored by at least one content repository 2708.

During initialization of system 2746, at least one content producer 2710provides digital content to at least one content repository 2708.Content repository 2708 stores the digital content in database 2738.Content producer 2710 also provides a description of the same content toat least one content provisioner 2724. Content descriptor loader 2718receives the content description and sends it to content catalog 2722 incontent provisioner 2724.

Turning now to FIG. 28, a flow diagram that illustrates a method fordigital content access control from the perspective of a user device inaccordance with one embodiment of the present invention is presented. At2800, a user device is received. At 2805, a user uses the user device toenroll with a content provisioner. During the enrollment process, theuser authenticates himself or herself to the content provisioner and mayprovide payment information such as authorization to charge a creditcard or authorization to debit a debit card or checking account fordigital content made accessible by tokens issued to the user.

Turning now to FIG. 29, a flow diagram that illustrates a method fordigital content access control from the perspective of a secure userdevice in accordance with one embodiment of the present invention ispresented. FIG. 29 corresponds with FIGS. 15 and 16. At 2900, a userdevice is received. At 2905, the user uses the user device to enrollwith a content provisioner. At 2910, the secret is stored for use inactivating tokens on a secure user device.

According to another embodiment of the present invention, enrolling witha content provisioner (2805, 2905) and receiving a secure user device(2800, 2900) is combined into one cryptographic process, such that auser receives a secure user device enabled to receive digital contentupon successfully enrolling with the content provisioner.

Turning now to FIG. 30, a flow diagram that illustrates a method forinitializing a digital content producer in accordance with oneembodiment of the present invention is presented. At 3000, digitalcontent is produced. By way of example, a digital music producer createsdigital files (such as MP3 files) that store musical content. At 3005,the content producer provides the digital content to a contentrepository. At 3010, the content producer provides a description of thedigital content to a content provisioner. Using the above example, thedigital content producer provides musical content such as digitalmusical tracks to the content repository. The content producer alsoprovides a description of the digital content (such as the artist andtitle of the musical tracks) to a content provisioner.

According to another embodiment of the present invention, a contentproducer provides digital content and a description of the digitalcontent to a synchronizer. The synchronizer generates token poolinformation associated with the digital content, sends the digitalcontent and token pool information to a content repository and sends thedigital content description and token pool information to a contentprovisioner.

Turning now to FIG. 31, a flow diagram that illustrates a method forinitializing a digital content provisioner in accordance with oneembodiment of the present invention is presented. At 3100, a token poolmessage is received from a synchronizer. The message may be encrypted.At 3105, token pool information is extracted from the pool message. At3110, the token issuer is initialized with token pool information fromthe token pool message.

Turning now to FIG. 32, a flow diagram that illustrates a method forcontent repository initialization in accordance with one embodiment ofthe present invention is presented. At 3200, digital content from acontent provider is received. At 3208, a token pool message from asynchronizer is received. The message may be encrypted. At 3210, tokenpool information is extracted from the token pool message. At 3215, atoken acceptor is initialized with the token pool information from thetoken pool message.

Turning now to FIG. 33, a flow diagram that illustrates a method forsynchronizer initialization in accordance with one embodiment of thepresent invention is presented. At 3300, a description of the digitalcontent to be protected is received. The description may comprise, byway of example, a URL, part of a URL, a summary of the digital content,a hash of the digital content, or the like. At 3300, token poolinformation is generated. At 3305, the token pool information is sent toone or more content provisioners. At 3310, the token pool information issent to one or more content repositories.

Turning now to FIG. 34, a detailed block diagram that illustrates asystem for digital content access control in accordance with oneembodiment of the present invention is presented. FIG. 34 illustratesusing tokens to access digital content once the system has beeninitialized as described with respect to FIGS. 27-33. In operation, userdevice 3400 sends a digital content request in the form of a URL tocontent provisioner 3404 via portal 3458. Download manager 3414 inprovisioner manager 3424 receives the URL and communicates with contentrights database 3422 to verify whether the user 3402 is authorized toaccess the digital content associated with the URL. If the user 3402 isauthorized to access the digital content associated with the URL,download manager 3414 sends a token request 3444 to token issuer 3420.Token issuer 3420 receives the token request 3444 and communicates withcontent catalog 3418 to obtain a token associated with the digitalcontent referenced by the URL. Token issuer 3420 sends the token 3446 todownload manager 3414. Download manager creates a tokenized URL 3448based at least in part on the URL 3440 and the token 3446 and sends thetokenized URL 3448 to user device 3400 via portal 3458. User device 3400sends the tokenized URL 3450 to content repository 3408 via network3406. Token acceptor 3432 in repository manager 3456 receives thetokenized URL 3450 and communicates with token pool 3440 in database3436 to determine whether the tokenized URL 3450 is valid. If thetokenized URL 3450 is valid, the digital content associated with thetokenized URL 3450 is obtained from digital content storage 3438 andsent to user device 3400 via network 3406.

Turning now to FIG. 35, a flow diagram that illustrates a method fordigital content access control from the perspective of a user device inaccordance with one embodiment of the present invention is presented.FIG. 35 illustrates operation of a user device in a system such assystem 370 in FIG. 3, where a content provisioner does not communicatedirectly with a content repository to obtain digital content associatedwith a digital content request. At 3500, a digital content request issent to a content provisioner capable of authenticating the request. At3505, an authenticated digital content request is received in responseto sending the digital content request. At 3510, the authenticateddigital content request is sent to a content repository that providesstorage for the digital content. At 3515, digital content correspondingto the authenticated digital content request is received in response tothe authenticated digital content request.

As mentioned above with respect to FIG. 4, according to one embodimentof the present invention, a requesting user device issues a digitalcontent request and a receiving user device receives digital content inresponse to the digital content request. In more detail with referenceto FIG. 35, the requesting user device (reference numeral 400 of FIG. 4)sends a digital content request (3500) to a content provisioner,receives an authenticated digital content request (3505) and sends theauthenticated digital content request to a content repository thatprovides storage for the digital content (3510). The authenticateddigital content request may comprise delivery information, or may beused to obtain delivery information. The delivery information mayindicate a receiving device that is different from the requestingdevice. The receiving user device (reference numeral 402 of FIG. 4)receives digital content corresponding to the digital content request(3515).

Turning now to FIG. 36, a flow diagram that illustrates a method fordigital content access control from the perspective of a user device inaccordance with one embodiment of the present invention is presented.FIG. 36 illustrates operation of a user device in a system such assystem 598 in FIG. 5, where a portal handles communication between acontent provisioner and a content repository to obtain digital contentassociated with a digital content request entered by a user. Accordingto one embodiment of the present invention, the portal that handlescommunications between a user device and a content provisioner alsohandles communications between the content provisioner and the contentrepository. At 3600, a digital content request is sent to a contentprovisioner capable of authenticating the request. At 3605, digitalcontent corresponding to the digital content is received in response tothe digital content request.

Turning now to FIG. 37, a flow diagram that illustrates a method fordigital content access control from the perspective of a secure userdevice in accordance with one embodiment of the present invention ispresented. FIG. 37 corresponds with FIGS. 15 and 16. At 3700, adeactivated token for accessing digital content is received. At 3705,the deactivated token is activated using a secret stored on the secureuser device. At 3710, an authenticated digital content request iscreated based at least in part on the activated token. At 3715, theauthenticated digital content request is sent to a content repositorythat provides storage for the digital content. At 3720, digital contentcorresponding to the digital content request is received.

Turning now to FIG. 38, a flow diagram that illustrates a method fordigital content access control from the perspective of a digital contentprovisioner in accordance with one embodiment of the present inventionis presented. At 3800, a request for access to digital content isreceived. At 3805, a determination is made regarding whether the userthat issued the request is authorized to access the digital content. Theresult of this determination is checked at 3810. If the requested accessis unauthorized, an exception is indicated at 3815. If the requestedaccess is authorized, an authenticated digital content request iscreated at 3820 and at 3825, the authenticated digital content requestis sent for use in accessing the digital content from a contentrepository. At 3830, a determination is made regarding whether poolsynchronization is enabled. Pool synchronization comprises determiningwhether additional tokens are required and requesting additional tokensif it is determined that more are required. If enabled, poolsynchronization is performed at 3835.

Turning now to FIG. 39, a flow diagram that illustrates a method fordigital content access control from the perspective of a digital contentprovisioner in accordance with one embodiment of the present inventionis presented. FIG. 39 corresponds with FIGS. 15 and 16. At 3900, arequest for access to digital content is received. At 3905, adetermination is made regarding whether the user that issued the requestis authorized to access the digital content. The result of thisdetermination is checked at 3910. If the requested access isunauthorized, an exception is indicated at 3915. If the requested accessis authorized, at 3920 a deactivated token is sent for use in accessingdigital content stored by a content repository. At 3925, a determinationis made regarding whether pool synchronization is enabled. If enabled,pool synchronization is performed at 3930.

Turning now to FIG. 40, a flow diagram that illustrates a method forcreating an authenticated digital content request in accordance with oneembodiment of the present invention is presented. FIG. 40 provides moredetail for reference numeral 3820 of FIG. 38. At 4000, the token poolassociated with the particular digital content is determined. At 4005,an unallocated token in the token pool is determined. At 4010, atokenized URL is created based at least in part on the token.

Turning now to FIG. 41, a flow diagram that illustrates a method fordigital content access control from the perspective of a digital contentrepository in accordance with one embodiment of the present invention ispresented. At 4100, an authenticated digital content request isreceived. At 4105, the authenticated digital content request isvalidated. At 4110, a determination is made regarding whether theauthenticated digital content request is valid. If the (authenticateddigital content request is invalid, an exception is indicated at 4115.If the authenticated digital content request is valid, a determinationis made regarding whether pool synchronization is enabled at 4120. Ifenabled, pool synchronization is performed at 4125. At 4130, the digitalcontent associated with the digital content request is provided.

FIGS. 42-50 illustrate validating an authenticated digital contentrequest in accordance with embodiments of the present invention. FIGS.42-50 provide more detail for reference numeral 4105 of FIG. 41. FIG. 42illustrates validating an authenticated digital content request using apre-computed token pool comprising multi-use tokens. FIGS. 43-47illustrate validating an authenticated digital content request bydynamically computing tokens using a sliding token offset window. FIG.48 illustrates validating an authenticated digital content request usinga pre-computed token pool comprising single-use tokens computed using acryptographic one-way function. FIG. 49 illustrates validating anauthenticated digital content request using a pre-computed token poolcomprising single-use tokens computed using a cryptographic one-wayfunction and ordered according to token redemption status. FIG. 50illustrates validating an authenticated digital content request bydynamically computing single-use tokens using a cryptographic one-wayfunction. These validation methods are explained in more detail below.

Turning now to FIG. 42, a flow diagram that illustrates a method forvalidating an authenticated digital content request using a pre-computedtoken pool comprising multi-use tokens in accordance with one embodimentof the present invention is presented. At 4200, a token is received. At4205, a determination is made regarding whether there are any unredeemedor partially redeemed tokens left in the token pool. If there is atleast one unredeemed or partially redeemed token remaining in the tokenpool, at 4210 a determination is made regarding whether the receivedtoken is in the token pool. If the received token is in the token pool,at 4215 a determination is made regarding whether the received token hasbeen fully redeemed. If the received token is fully redeemed at 4215, orif the received token is not in the token pool at 4210, or if there areno unredeemed tokens left to check at 4205, at 4230 an indication thatthe received token is invalid is made. If at 4215 the received token hasnot been fully redeemed, a token redemption count associated with thereceived token is incremented at 4220, and an indication that thereceived token is valid is made at 4225.

FIGS. 43-46 illustrate using a sliding token offset window for dynamictoken computation in accordance with one embodiment of the presentinvention. FIG. 43 depicts a sliding token offset window, and FIG. 44illustrates a method for using a sliding token offset window. FIG. 45illustrates a method for validating an authenticated digital contentrequest by dynamically computing tokens using a sliding token offsetwindow having a dynamic size. FIG. 46 illustrates a method forvalidating an authenticated digital content request by dynamicallycomputing tokens using a sliding token offset window having a staticsize.

According to embodiments of the present invention, a window managementpolicy determines the criteria for moving the bottom of the window andthe top of the window. The window may be moved as part of a tokensynchronization process. The window may also be moved as part of a tokenvalidation process.

According to embodiments of the present invention, the criteria formoving the bottom or top of a window may be based at least in part onthe amount of time since the window was last moved.

Turning now to FIG. 43, a block diagram that illustrates a sliding tokenoffset window for use in dynamic token computation in accordance withone embodiment of the present invention is presented. As shown in FIG.43, data structure 4300 comprises a list of offset entries 4302-4334.Sliding window 4334 comprises a predetermined number of offset entries.Offset entries within window 4334 are identified by a base number 4336and an offset 4338 from the base number. The offsets for entries 4324,4322, 4320, 4318, 4316, 4314, 4312 and 4310 are 0-7, respectively.According to one embodiment of the present invention, the ordinal numberof an identifier in a series comprises the sum of an offset 4338 and abase number 4336. Similarly, the offset 4338 comprises the ordinalnumber of the identifier in a series, minus the base number 4336.

Still referring to FIG. 43, an offset entry is associated with an offsetredemption status. According to one embodiment of the present invention,a token may be redeemed a predetermined number of times. In this case,the possible offset redemption status values comprise an “unredeemed”status, a “partially redeemed” status and a “fully redeemed” status.According to another embodiment of the present invention, a token may beredeemed once. In this case, the possible token redemption status valuescomprise a “fully redeemed” status and a “not fully redeemed” status. Anoffset is fully redeemed if a token based at least in part on the offsethas been redeemed a predetermined number of times. An offset is notfully redeemed if a token based at least in part on the offset has beenredeemed less than the predetermined number of times. An offset ispartially redeemed if a token based at least in part on the offset hasbeen redeemed a number of times that is greater than zero but less thanthe predetermined number of times.

According to embodiments of the present invention, data structure 4300is used to determine whether a received token has been fully redeemed.The determination comprises summing the base number 4336 and an offsetwithin sliding window 4334, where the offset has an offset redemptionstatus of “unredeemed” or “partially redeemed”. The sum is used as aninput to a cryptographic process that computes a token. If the result ofthe cryptographic process matches the received token, a valid token isindicated and the offset redemption status of the offset is updated toaccount for the redemption. This process is explained in more detailbelow with reference to FIG. 44.

Turning now to FIG. 44, a flow diagram that illustrates a method forvalidating an authenticated digital content request by dynamicallycomputing tokens using a sliding token offset window in accordance withone embodiment of the present invention is presented. At 4400, a tokenis received. At 4405, a determination is made regarding whether thereare any unredeemed or partially redeemed offsets within an offsetwindow. If there is at least one unredeemed or partially redeemed offsetwithin the offset window, at 4410 an offset within the window that hasnot been fully redeemed is selected. At 4415, a cryptographic process isapplied to the sum of the base number and the selected offset. At 4420,a determination is made regarding whether the result of thecryptographic process matches the received token. If there is no match,another offset is selected beginning at 4405. If there is a match, theoffset redemption status of the selected offset is updated at 4425 toaccount for the redemption and at 4430, an indication that the receivedtoken is valid is made. If none of the results of applying thecryptographic process to the sum of the base number and each unredeemedor partially redeemed offsets match the received token, an indicationthat the received token is invalid is made at 4435.

FIGS. 45 and 46 are similar to FIG. 44, except that the received tokenin FIGS. 45 and 46 comprises token offset information, as illustratedabove with respect to FIGS. 18D and 18E. Additionally, the windows inFIGS. 45 and 46 are modified when the offset is above the token window.In FIG. 45, the window is expanded upwards to include the offset. InFIG. 46, the window is moved upwards to include the offset.

Turning now to FIG. 45, a flow diagram that illustrates a method forvalidating an authenticated digital content request by dynamicallycomputing tokens using a sliding token offset window having a dynamicsize in accordance with one embodiment of the present invention ispresented. At 4500, a token comprising token offset information isreceived. At 4505, a determination is made regarding whether the offsetis within a token offset window. If the offset is not within the tokenoffset window, at 4510 a determination is made regarding whether theoffset is above the window. If the token is not above the window, anindication that the token is invalid is made at 4540. If the offset isabove the window, at 4515 the window is expanded upwards to include theoffset. At 4520, a cryptographic process is applied to the sum of thebase number and the offset. At 4525, a determination is made regardingwhether the result of the cryptographic process matches the receivedtoken. If there is no match, an indication that the token is invalid ismade at 4540. If there is a match, at 4545 a determination is maderegarding whether the token is fully redeemed. If the token is fullyredeemed, an indication that the token is invalid is made at 4540. Ifthe token is not fully redeemed, the offset redemption status of theoffset is updated at 4530 to account for the redemption and at 4535, anindication that the received token is valid is made.

Turning now to FIG. 46, a flow diagram that illustrates a method forvalidating an authenticated digital content request by dynamicallycomputing tokens using a sliding token offset window having a staticsize in accordance with one embodiment of the present invention ispresented. FIG. 46 is similar to FIG. 45, except that the window ismoved upwards to include the offset (4615) when the offset is above thewindow in FIG. 46, whereas the window is expanded upwards to include theoffset (4515) when the offset is above the window in FIG. 45.

Turning now to FIG. 47, a flow diagram that illustrates a method forupdating an offset in accordance with one embodiment of the presentinvention is presented. FIG. 47 provides more detail for referencenumerals 4425, 4530 and 4630 of FIGS. 44, 45 and 46, respectively. At4700, the redemption status of the offset is updated. At 4705, adetermination is made regarding whether the offset is at the bottom ofthe window. If the offset is at the bottom of the window, the window ismoved upwards. According to one embodiment of the present invention, thewindow is moved up one position. According to another embodiment of thepresent invention, the window is moved up until the bottom of the windowcomprises an unredeemed or partially redeemed offset.

Turning now to FIG. 48, a flow diagram that illustrates a method forvalidating an authenticated digital content request using a pre-computedtoken pool comprising single-use tokens computed using a cryptographicone-way function in accordance with one embodiment of the presentinvention is presented. At 4800, a token is received. At 4805, adetermination is made regarding whether there are any unredeemed tokensleft in the token pool. If there is at least one unredeemed tokenremaining in the token pool, at 4810 a determination is made regardingwhether the received token is in the token pool. If the received tokenis in the token pool, at 4815 a determination is made regarding whetherthe token has been redeemed. If the token has not been redeemed, at 4820an indication is made that the token is valid. At 4825, tokens in thetoken chain that were generated after the received token areinvalidated. If there are no tokens left to check at 4805, or if thereceived token is not in the token pool at 4810, or if the receivedtoken has been redeemed (4815), an indication that the token is invalidis made at 4830.

Turning now to FIG. 49, a flow diagram that illustrates a method forvalidating an authenticated digital content request using a pre-computedtoken pool comprising single-use tokens computed using a cryptographicone-way function and ordered according to token redemption status inaccordance with one embodiment of the present invention is presented. At4900, a token is received. At 4905, a determination is made regardingwhether there are any unredeemed tokens left in the token pool. If thereis at least one unredeemed token remaining in the token pool, at 4910 adetermination is made regarding whether the received token is in aportion of the token pool comprising redeemed tokens. If the receivedtoken has not been redeemed, at 4915 an indication that the receivedtoken is valid is made. At 4920, the tokens of the token pool arereordered based upon their token redemption status. If there are notokens left to check at 4905, or if the token has been redeemed (4910),an indication that the token is in valid is made at 4925.

Turning now to FIG. 50, a flow diagram that illustrates a method forvalidating an authenticated digital content request by dynamicallycomputing single-use tokens using a cryptographic one-way function inaccordance with one embodiment of the present invention is presented. At5000, a token is received. At 5005, the current token is set to thereceived token. At 5010, a determination is made regarding whether thereare any unredeemed tokens left in a token pool. If there is at least oneunredeemed token remaining, at 5015 a determination is made regardingwhether the received token matches the last redeemed token. If thereceived token does not match the last received token, at 5020 thecurrent token is set to the result of applying a cryptographic one-wayfunction to the current token. At 5025, a determination is maderegarding whether the current token matches the last redeemed token. Ifthe current token matches the last redeemed token, an indication thatthe token is valid is made at 5035 and the last redeemed token is set tothe received token at 5040. If the current token does not match the lastredeemed token at 5025, at 5030 a determination is made regardingwhether there is another unredeemed token in the token pool. If there isanother token in the token pool, the next token is checked beginning at5020. If there are no more tokens in the token pool at 5030, or if thereceived token matches the last redeemed token at 5015, or if there areno tokens left to check at 5010, an indication that the token is invalidis made at 5045.

FIGS. 42, 44, 48, 49 and 50 include an initial determination regardingwhether there are any tokens or offsets left to be checked (referencenumerals 4205, 4405, 4805, 4905 and 5010, respectively). Thisdetermination may comprise checking a variable comprising this tokeninformation. Alternatively, the determination may comprise searching forone or more tokens or offsets that have not been fully redeemed.

Turning now to FIG. 51, a flow diagram that illustrates a method fordigital content access control from the perspective of a synchronizer inaccordance with one embodiment of the present invention is presented. At5100, a determination is made regarding whether a synchronization eventhas been received. According to one embodiment of the present invention,a synchronization event comprises the receipt of a synchronizationrequest. According to another embodiment of the present invention, asynchronization event is generated at predetermined intervals. If asynchronization event has been received, at 5105 token pool informationis determined. At 5110, a determination is made regarding whether thesynchronization event is an internal event. A synchronization event isan internal event if it is triggered by the synchronizer. An exemplaryinternal event is a synchronization event triggered by the synchronizerat a predetermined interval. A synchronization event is an externalevent if it is triggered by an entity other than the synchronizer. Ifthe synchronization event is an internal event, at 5115 token poolinformation is sent to all entities that need to know the information.If the synchronization event is not an internal event, at 5120 the tokenpool information is sent to a possible requesting party. The requestingparty may be, by way of example, a content provisioner or a contentrepository. At 5125, a determination is made regarding whether the tokenpool information should be sent to a non-requesting party. If the tokenpool information should be sent to the non-requesting party, it is doneat 5130.

According to one another embodiment of the present invention, token poolinformation determined in response to a synchronization request is sentto the requesting party. By way of example, upon receiving asynchronization request from a content provisioner, the synchronizersends token pool information to the content provisioner.

According to another embodiment of the present invention, token poolinformation determined in response to a synchronization request is sentto both the requesting party and one or more non-requesting partiesregardless of the identity of the requesting party. By way of example,upon receiving a synchronization request from a content provisioner, thesynchronizer sends token pool information to both the contentprovisioner and a content repository.

While embodiments and applications of this invention have been shown anddescribed, it would be apparent to those skilled in the art having thebenefit of this disclosure that many more modifications than mentionedabove are possible without departing from the inventive concepts herein.The invention, therefore, is not to be restricted except in the spiritof the appended claims.

1. A method for distributing digital content access control information,the method comprising: applying a cryptographic process to at least partof a Universal Resource Locator (URL) together with a secret key tocreate a token chain key, wherein said URL identifies protected digitalcontent; said token chain key is for use in creating a plurality oftokens in a token chain wherein said token chain is associated with saidprotected digital content; and said plurality of tokens are eachredeemable for access to said protected digital content; and sendingsaid token chain key to an entity capable of applying said token chainkey to validate said each of said plurality of tokens.
 2. The method ofclaim 1 wherein said at least part of a URL comprises a content domainindicator.
 3. The method of claim 1 wherein said at least part of a URLcomprises: a content domain indicator; and a content directoryindicator.
 4. The method of claim 1 wherein said at least part of a URLcomprises: a content domain indicator; a content directory indicator;and a content item indicator.
 5. A method for distributing digitalcontent access control information, the method comprising: applying acryptographic process to at least part of a Universal Resource Locator(URL) together with a secret key to create a token chain key, whereinsaid URL identifies protected digital content; said token chain key isfor use in creating a plurality of tokens in a token chain wherein saidtoken chain is associated with said protected digital content; and eachof said plurality of tokens redeemable for access to said protecteddigital content; encrypting said token chain key and a chain lengthvalue with a shared transport key to create sealed token poolinformation, said chain length value indicating the length of said tokenchain; and sending said sealed token pool information to an entitycapable of applying said token chain key to validate said each of saidplurality of tokens.
 6. A method for distributing digital content accesscontrol information, the method comprising: step for applying acryptographic process to at least part of a Universal Resource Locator(URL) together with a secret key to create a token chain key, whereinsaid URL identifies protected digital content; said token chain key isfor use in creating a plurality of tokens in a token chain wherein saidtoken chain is associated with said protected digital content; and saidplurality of tokens are each redeemable for access to said protecteddigital content; and step for sending said token chain key to an entitycapable of applying said token chain key to validate said each of saidplurality of tokens.
 7. The method of claim 6 wherein said at least partof a URL comprises a content domain indicator.
 8. The method of claim 6wherein said at least part of a URL comprises: a content domainindicator; and a content directory indicator.
 9. The method of claim 6wherein said at least part of a URL comprises: a content domainindicator; a content directory indicator; and a content item indicator.10. A method for distributing digital content access controlinformation, the method comprising: step for applying a cryptographicprocess to at least part of a Universal Resource Locator (URL) togetherwith a secret key to create a token chain key, wherein said URLidentifies protected digital content; said token chain key is for use increating a plurality of tokens in a token chain wherein said token chainis associated with said protected digital content; and each of saidplurality of tokens redeemable for access to said protected digitalcontent; step for encrypting said token chain key and a chain lengthvalue with a shared transport key to create sealed token poolinformation, said chain length value indicating the length of said tokenchain; and step for sending said sealed token pool information to anentity capable of applying said token chain key to validate said each ofsaid plurality of tokens.
 11. A program storage device readable by amachine, embodying a program of instructions executable by the machineto perform a method for distributing digital content access controlinformation, the method comprising: applying a cryptographic process toat least part of a Universal Resource Locator (URL) together with asecret key to create a token chain key, wherein said URL identifiesprotected digital content; said token chain key is for use in creating aplurality of tokens in a token chain wherein said token chain isassociated with said protected digital content; and said plurality oftokens are each redeemable for access to said protected digital content;and sending said token chain key to an entity capable of applying saidtoken chain key to validate said each of said plurality of tokens. 12.The program storage device of claim 11 wherein said at least part of aURL comprises a content domain indicator.
 13. The program storage deviceof claim 11 wherein said at least part of a URL comprises: a contentdomain indicator; and a content directory indicator.
 14. The programstorage device of claim 11 wherein said at least part of a URLcomprises: a content domain indicator; a content directory indicator;and a content item indicator.
 15. A program storage device readable by amachine, embodying a program of instructions executable by the machineto perform a method for distributing digital content access controlinformation, the method comprising: applying a cryptographic process toat least part of a Universal Resource Locator (URL) together with asecret key to create a token chain key, wherein said URL identifiesprotected digital content; said token chain key is for use in creating aplurality of tokens in a token chain wherein said token chain isassociated with said protected digital content; and each of saidplurality of tokens redeemable for access to said protected digitalcontent; encrypting said token chain key and a chain length value with ashared transport key to create sealed token pool information, said chainlength value indicating the length of said token chain; and sending saidsealed token pool information to an entity capable of applying saidtoken chain key to validate said each of said plurality of tokens. 16.An apparatus for distributing digital content access controlinformation, the apparatus comprising: means for applying acryptographic process to at least part of a Universal Resource Locator(URL) together with a secret key to create a token chain key, whereinsaid URL identifies protected digital content; said token chain key isfor use in creating a plurality of tokens in a token chain wherein saidtoken chain is associated with said protected digital content; and saidplurality of tokens are each redeemable for access to said protecteddigital content; and means for sending said token chain key to an entitycapable of applying said token chain key to validate said each of saidplurality of tokens.
 17. The apparatus of claim 16 wherein said at leastpart of a URL comprises a content domain indicator.
 18. The apparatus ofclaim 16 wherein said at least part of a URL comprises: a content domainindicator; and a content directory indicator.
 19. The apparatus of claim16 wherein said at least part of a URL comprises: a content domainindicator; a content directory indicator; and a content item indicator.20. An apparatus for distributing digital content access controlinformation, the apparatus comprising: applying a cryptographic processto at least part of a Universal Resource Locator (URL) together with asecret key to create a token chain key, wherein said URL identifiesprotected digital content; said token chain key is for use in creatingone or more tokens in a token chain wherein said token chain isassociated with said protected digital content; and said one or moretokens redeemable for access to said protected digital content;encrypting said token chain key and a chain length value with a sharedtransport key to create sealed token pool information, said chain lengthvalue indicating the length of said token chain; and sending said sealedtoken pool information to an entity capable of applying said token chainkey to validate said one or more tokens.
 21. An apparatus fordistributing digital content access control information, the apparatuscomprising: a memory for storing a shared key; and a synchronizerconfigured to: apply a cryptographic process to at least part of aUniversal Resource Locator (URL) together with a secret key to create atoken chain key, wherein said URL identifies protected digital content;said token chain key is for use in creating a plurality of tokens in atoken chain wherein said token chain is associated with said protecteddigital content; and said plurality of tokens are each redeemable foraccess to said protected digital content; and send said token chain keyto an entity capable of applying said token chain key to validate saideach of said plurality of tokens.
 22. The apparatus of claim 21 whereinsaid at least part of a URL comprises a content domain indicator. 23.The apparatus of claim 21 wherein said at least part of a URL comprises:a content domain indicator; and a content directory indicator.
 24. Theapparatus of claim 21 wherein said at least part of a URL comprises: acontent domain indicator; a content directory indicator; and a contentitem indicator.
 25. An apparatus for distributing digital content accesscontrol information, the apparatus comprising: a memory for storing ashared key; a synchronizer configured to: apply a cryptographic processto at least part of a Universal Resource Locator (URL) together with asecret key to create a token chain key, wherein said URL identifiesprotected digital content; said token chain key is for use in creating aplurality of tokens in a token chain wherein said token chain isassociated with said protected digital content; and each of saidplurality of tokens redeemable for access to said protected digitalcontent; encrypt said token chain key and a chain length value with ashared transport key to create sealed token pool information, said chainlength value indicating the length of said token chain; and send saidsealed token pool information to an entity capable of applying saidtoken chain key to validate said each of said plurality of tokens.